<div class="box">
  <h4 class="box-item" style="text-align: center;">这是子组件</h4>
  <div class="box-item">title：{{title}}</div>
  <div class="box-item">
    <button (click)="parentRun()">触发父组件方法</button>
  </div>
  <div class="box-item">parent.data：{{parent.data}}</div>
</div>
